Throw in the Sponge! Trivia Quiz

Answer: Porifera

The word "Porifera" comes from the Latin words "porus" (meaning "pore") and "ferre" (meaning "to bear"). All species within Porifera are considered sponges. The sponges are generally regarded as the least evolutionary advanced animals on Earth today.

Cnidaria is the phylum containing the jellyfishes. Ctenophora is the phylum containing the comb jellies. Arthropoda is the phylum containing the arachnids, insects, crustaceans, etc.

Answer: sea slugs

Sponges eat by filtering the water flowing through them for small bacteria, crustaceans, plankton, and other organic particles. Sponges also breathe and excrete waste in the same way. However, they typically prefer relatively still water, so as to avoid too much silt clogging their pores. The sponges have many small flagella with which they propel water through their porous bodies. Food particles are trapped by the sponges' choanocytes, commonly called "collar cells".

Sponges do not eat sea slugs. In fact, it's quite the other way around; nudibranch sea slugs are one of the main predators of many sponges.

Answer: lack of true tissues

The cells of sponges are not organized into specialized tissues, which are found in all other animals. This lacking feature is commonly referenced by those who argue that the sponges should not be classified as animals. However, they continue to be considered animals mostly because they are multicellular, eukaryotic, have specialized individual cells, show some motility, and are heterotrophic (they rely on other organisms for food). In addition, ribosomal and genetic evidence shows that they are indeed more closely related to the other animals than plants, fungi, or the other kingdoms.

Many other animals are also filter feeders, including krill, clams, some fish, and even baleen whales and flamingos!

A few other animals are also sessile (not able to move) for some or even all of their lifetime. These include barnacles, corals, and some hydra.

Some other animals also lack circulatory systems, such as hydra and planaria.

Answer: burrowing into the sand

Sponges can actually move in all of the ways listed above, except for burrowing into the sand. The larvae of sexually reproducing sponges swim freely in search of a place to plant themselves, and often even crawl along the bottom. Some adult sponges can slowly "slide" along the ocean or lake floor, although only at a rate of a few millimeters per day.

Many species of sponge open and close their oscula and ostia, which are types of pores through which water flows.

Answer: False

Even though it more or less resembles a sponge, the loofah is made from the fibrous outer parts of a fruit. The fruit grows on a tropical vine of the genus Luffa. The gourd-like fruit is processed to remove all but the fibrous xylem, which then becomes the household product known as the "loofah".

Answer: bottlenose dolphin

Incredibly, a small group of bottlenose dolphins (genus Turslops) has been observed using sponges as tools. The dolphin attaches a sponge to its rostrum (its beak), most likely to protect it while stirring up the ocean floor in search of food. This behavior is almost always exhibited by female dolphins, and is taught from mother to daughter. This has only been observed in Shark Bay, a body of water in Western Australia, and only within a small group of closely related individuals.

While not sponge-related, I feel that the veined octopus is worth mentioning in a bit more detail here. This species is also called the coconut octopus, as it is commonly observed gathering coconut shells and forming a shelter with them. This octopus is the first known invertebrate to use tools. Who knows, maybe it will someday find a use for sponges!

Answer: spongillafly

Sometimes called "sponge flies", these winged insects of the family Sisyridae are highly specialized towards predation of sponges. During their larval stage, these flies eat almost nothing other than freshwater sponges of the genus Spongilla. The adult flies lay eggs on vegetation hanging over the water, which then hatch, and the larvae drop into the water. The larvae have mouthparts which have evolved specifically to be able to pierce sponges and "drink" their cell contents. These fly larvae sometimes also feed upon freshwater bryozoans. Spongillaflies are part of the insect order Neuroptera, which also includes lacewings, antlions, and mantidflies.

Sponges are also quite adept at healing and regrowing themselves, often faster than the predator can eat them!

Water striders, rove beetles, and non-biting midges are also aquatic (and some are marine) groups of insects, but none of these feed upon sponges.

Answer: Hexactinellida

Hexactinellida is a class of sponges commonly called "glass sponges". They are characterized by their cup shape, and their four- or six-pointed spicules made of silica. These sponges mostly live in fairly deep ocean water. Most glass sponges grow quite slowly, which causes their age estimates to sometimes be quite large. One antarctic specimen of Scolymastra joubini was estimated to be 23,000 years old based on growth rates. However, most experts cap its possible age at around 15,000 years due to the sea level fluctuations in that particular area.

Calcarea is the class of sponges known as "calcareous sponges". Their distinguishing features are their spicules made of calcium carbonate, with two to four points.

Demospongiae is the largest class of sponges, commonly known as "demosponges". These sponges are characterized by spicules made of spongin protein, silica, or both.

Sclerospongiae, commonly called "coralline sponges", was once considered a class of sponges, but is no longer recognized as such. The former members of this defunct class are now scattered across the other three sponge classes, echoing the fact that the sclerospongiae were not closely related enough to form their own class.

Answer: ink clouds

Sponges have been around the predator-filled oceans for at least 700 million years (and probably twice that long). Thus, it stands to reason that they must have evolved some quite successful defenses.

Perhaps the most common is production of toxic chemicals. Most sponges produce chemicals in order to kill bacteria, fungi, algae, coral, or even other sponge species, thus gaining more space for their own growth. Often times a sponge species produces a specific chemical which deters a specific predator common to the sponge's habitat. In reciprocation, sometimes the predator has evolved immunity to the sponge's toxins. This is a prime example of what biologists call an "evolutionary arms race", wherein two or more species in a predator-prey relationship will continually evolve more complex and potent offenses and defenses in response to one another.

Some sponges also have rather sharp spicules which can provide deterrence against larger animals eating them, by simply causing the predator pain or difficulty upon biting and/or swallowing. Some sponges also shed their spicules, eventually forming deep carpets that can prove difficult for predatory echinoderms to traverse.

Ink clouds are well known as one of the octopus's main defense mechanisms. However, no sponges can produce ink like this. Sponges lack the true tissue and organ systems that would likely be necessary for such a complicated function.

Answer: Venus's Flower Basket

The Venus's Flower Basket (Euplectella aspergillum) is a delicate, tubular, lace-like sponge that lives in a fascinating symbiosis with a single mated pair of shrimp. The shrimp benefit from having food constantly available in the hollow interior of the sponge, as well as gaining protection from predators. The sponge benefits from having its pores cleaned by the shrimp. The pair of shrimp spend their entire lives in the sponge, eventually producing offspring which promptly leave in search of their own Venus's Flower Basket sponge. The Venus's Flower basket lives in fairly deep waters near Japan and the Philippines. This once quite expensive sponge is sometimes given as a wedding gift in Asian cultures, due to its symbolism of lasting love.

Many sponges exhibit symbiotic relationships with other species. A single sponge was once found to contain over 16,000 distinct species living within its body!

All of the three incorrect answers are made-up names that I derived from other Roman and Greek deities of love.